One vertex per element, one color per generator, with an edge from x to x·s.
(9,10,14,15)(11,12,16,20)(13,21,23,17)(18,22,24,19)(25,26)(27,34)(28,36)(29,32)(30,33)(31,37)(35,38)(39,40)(1,2)(3,4)(5,7)(6,8)(9,11)(10,12)(13,18)(14,16)(15,20)(17,19)(21,22)(23,24)(25,27,30,32)(26,29,33,34)(28,35,37,39)(31,38,36,40)(1,3,5,8)(2,6,7,4)(10,15)(11,16)(17,21)(18,24)(28,37)(31,36)(35,39)(38,40)(3,8)(4,6)(9,11)(10,12)(13,18)(14,16)(15,20)(17,19)(21,22)(23,24)(25,28)(26,31)(27,35)(29,38)(30,37)(32,39)(33,36)(34,40) involution — undirected(1,4)(2,3)(5,6)(7,8)(9,12)(10,16)(11,15)(13,22)(14,20)(17,18)(19,23)(21,24)(25,26)(27,29)(28,36)(30,33)(31,37)(32,34)(35,40)(38,39) involution — undirected(1,2)(3,6)(4,8)(5,7)(9,13,14,23)(10,17,15,21)(11,18,16,24)(12,19,20,22)(25,29)(26,32)(27,33)(28,38)(30,34)(31,39)(35,36)(37,40)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.